It has been heretofore proposed to promote the growth of oxide coatings on silicon wafers by the use of high-pressure steam, see "Oxidation of Silicon by High-Pressure Steam," by Ligenza, Bell Telephone Laboratories, pages 73-76, Journal of the Electrochemical Society, February, 1962; "High Pressure Steam Apparatus for the Accelerated Oxidation of Silicon," by Panousis and Schneider, Bell Telephone Laboratories, Spring Meeting of the Electrochemical Society in Chicago, May 13-18, 1973; and "Selective Oxidation of Silicon in Low-Temperature High-Pressure Steam," authored by Powell, Ligenza and Schneider and published in IEEE Transactions on Electron Devices, Vol. ED-21, No. 10, October, 1974. High-pressure steam systems, while demonstrated in the laboratory, have not been available in commercial structures; nor has anyone succeeded in providing such high-pressure steam treatment on a continuous production basis wherein such high-pressure steam is introduced into and caused to flow continuously through a reaction chamber containing the wafers and wherein pressure equilization is maintained across the wall of the vessel providing the reaction chamber to permit the use of an otherwise fragile quartz vessel.
A successful continuous flow-through system is disclosed in U.S. Pat. No. 4,167,915 which provides for the introduction into and the continuous flow through the silicon wafer reaction chamber of hydrogen and oxygen gases functioning by pyrosynthesis to promote oxide growth.
As the principal feature of the present invention, a continuous flow-through system is provided utilizing high-pressure water vapor as the activating oxide-forming media.
The invention possesses other objects and features of advantage, some of which of the foregoing will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part of this specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims.